System and method for splitting an image across multiple computer readable media

ABSTRACT

A software tool and method in which a source image is split into and spans across two or more image pieces having a data structure which fits onto a computer readable medium having an available storage capacity which is smaller than the size of the source image. Also, software tool and method which combines two or more image pieces of a source image on a destination medium into a re-combined image having a data structure corresponding to the source image.

TECHNICAL FIELD

The present invention relates to the field of image spanning. Inparticular, this invention relates to a system and method for splittinga single file image into operationally usable pieces across multipleremovable computer readable media.

BACKGROUND OF THE INVENTION

Software products are becoming increasingly large and frequently largerthan the capacity of a single computer readable medium such as amagnetic or optical disk. As a result, such software products do not fitonto a single medium. In the past, when a copy of such a softwareproduct was needed, the product was split into two or more pieceswherein each piece was equal to or less than the capacity of the medium.The content of each piece was arbitrarily selected. Each piece was thencopied onto a separate medium. To re-create the software program, thepieces on the separate medium were used to re-assemble the softwareprogram. When software programs are split in this manner, it is verydifficult if not impossible to determine which files of the softwareprogram are stored on a particular medium.

Furthermore, the images of such software products do not fit onto asingle medium. The prior art does not address splitting or spanning animage of a software program into two or more pieces wherein each pieceof the image is equal to or less than the capacity of the medium so thateach piece may be copied onto a separate medium. Also, the prior art isnot able to re-create the software program from the pieces of the image.Furthermore, there is a need for splitting an image of a softwareprogram into two or more pieces wherein each piece of the image is equalto or less than the capacity of the media in such a way that it can bedetermined which files of the software program are stored on aparticular medium.

For these reasons, a system and method for splitting images is desiredto address one or more of these and other disadvantages.

SUMMARY OF THE INVENTION

The invention includes software image spanning to permit a single fileimage to be split into operationally usable pieces across multipleremovable media. In particular, the invention includes softwarefunctionality that allows a single file image to be split into piecesthat fits on multiple fixed sized removable media.

The invention contemplates many embodiments to optimally group necessaryfiles on a common medium, and to allow files required to make a mediumbootable to exist within a single image and to duplicate only necessarycomponents on subsequent media.

Among the advantages of the invention would be allowing the image to besplit and chained in a way that not only allows each image piece to bemodified, updated or restored without being reassembled, but also allowsthe individual pieces of the image to be opened or mounted so thatindividual files within the image can be added to, removed from, orextracted from the image. Another advantage is the convenience of savinglarge images to multiple media.

Creating a way to specify which files are part of an image piece of theimage that will be copied to a particular media allows for manyimportant scenarios. For example, the scenarios include, but are notlimited to, allowing files required to make a medium bootable to existinside a first piece of the image and not take up duplicate space onother media; including all the files required by an application programin a first piece so that the application can initiate operation withoutchanging media; or grouping component resources in a single piece somedia changing is kept to a minimum.

In one form, the invention is a software tool which splits a sourceimage into two or more image pieces, each of which fits onto a computerreadable medium having an available storage capacity which is smallerthan the size of the source image. The software tool comprises aselecting tool responsive to user input for designating which files ofthe source image to be included in each image piece, a splitting toolwhich groups the designated files into their corresponding image pieceand a chaining tool which labels each of the image pieces.

In another form, the invention is a method of splitting a source imageinto two or more image pieces, each of which fits onto a computerreadable medium having an available storage capacity which is smallerthan the size of the source image. The method comprises designatingwhich files of the source image to be included in each image piece andgrouping the designated files into their corresponding image pieces.

In another form, the invention is a method of creating from a sourceimage an image piece which fits onto a computer readable medium havingan available storage capacity which is smaller than the size of thesource image. The method comprises:

-   -   specifying the size of the image piece;    -   designating which files of the source image to be included in        the image piece;    -   creating the image piece from the designated files;    -   writing a header for the image piece wherein the header        corresponds to the designated files;    -   writing a metadata for the image piece wherein the metadata        corresponds to the designated files;    -   copying priority data which corresponds to the designated files        from the source image to the image piece;    -   copying non-priority data from the source image to the image        piece; and    -   adding a signature to the image piece which signature        corresponds to the contents of the image piece.

In another form, the invention is a computer readable medium havingstored thereon a data structure representing a image piece of a sourceimage comprising selected files of the source image, a headeridentifying the image piece as a portion of the source image, a metadataidentifying the files of the image piece, priority data from the sourceimage corresponding to the selected files, non-priority data from thesource image, and a signature corresponding to the image piece.

In another form, the invention is a software tool having computerexecutable components for combining two or more image pieces of a sourceimage into a re-combined image corresponding to the source image. Eachof the image pieces is on a computer readable medium having an availablestorage capacity which is smaller than the size of the source image. There-combined image is stored on a destination computer readable medium.The software tool comprises a copying tool, a combining tool and achaining tool. The copying tool is responsive to user input for copyingfiles of the image pieces onto the destination computer readable medium.The combining tool combines the copied files into the re-combined imageon the destination computer readable medium. The chaining tool labelsthe re-combined image on the destination computer readable medium.

In another form, the invention is a method of combining two or moreimage pieces of a source image into a re-combined image corresponding tothe source image. Each of the image pieces is stored on a computerreadable medium having an available storage capacity which is smallerthan the size of the source image. The re-combined image is on adestination computer readable medium. The method comprises:

-   -   copying files of the image pieces onto the destination computer        readable medium in response to user input;    -   combining the copied files into the re-combined image on the        destination computer readable medium; and    -   labeling the re-combined image on the destination computer        readable medium.

In another form, the invention is a method of combining two or moreimage pieces of a source image into a re-combined image corresponding tothe source image. Each of the image pieces is on a computer readablemedium having an available storage capacity which is smaller than thesize of the source image. The re-combined image is on a destinationcomputer readable medium. The method comprises:

-   -   imaging the re-combined image from the image pieces;    -   writing a header for the re-combined image wherein the header        corresponds to the files of the re-combined image;    -   writing a metadata for the image piece wherein the metadata        corresponds to the files of the re-combined image;    -   adding a signature to the re-combined image which signature        corresponds to the contents of the re-combined image.

In another form, the invention is a computer readable medium havingstored thereon a data structure representing a re-combined image formedby combining two or more image pieces of a source image. The re-combinedimage corresponds to the source image, wherein each of the image piecesis stored on a computer readable medium having an available storagecapacity which is smaller than the size of the source image. There-combined image is on a destination computer readable medium. The datastructure comprises a header identifying the re-combined image, ametadata identifying the files of the re-combined image, priority datafrom the image pieces, non-priority data from the image pieces, and asignature corresponding to the re-combined image.

In another form, the invention is a computer-readable medium havingstored thereon a first image piece of a software image which first imagepiece can be combined with one or more other image pieces of thesoftware image into a combined image which corresponds to the softwareimage. The medium comprises an image of descriptive data of the softwareimage and an image of file data of the software image.

In another form, the invention is a combined image including a firstimage piece of a software image and including a second image piece ofthe software image. The combined image comprises a header of thecombined image, a first metadata of the first image piece, a secondmetadata of the second image piece, a first file data of file data ofthe first image piece, a second file data of file data of the secondimage piece and a signature of the combined image.

Alternatively, the invention may comprise various other methods andapparatuses.

Other features will be in part apparent and in part pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary diagram illustrating the conversion of a softwareprogram to a source image which can be split into image pieces accordingto the invention.

FIG. 2 is an exemplary flow chart illustrating operation of one methodand tool according to the invention for creating a source image whichcan be split into image pieces.

FIG. 3 is an exemplary embodiment of the invention illustratingschematically the layout of image pieces 1, 2 and 3 on destinationcomputer readable media #1, #2 and #3, respectively, from a source imageon a source computer readable medium.

FIG. 4 is exemplary flow chart illustrating operation of a method andtool according to the invention for creating image pieces, each on aseparate computer readable medium, from a source image according to theinvention.

FIG. 5 is a block diagram illustrating an exemplary destinationcomputer-readable medium on which a re-combined image corresponding tothe source image may be created from image pieces which are each on aseparate computer readable medium, according to the invention.

FIG. 5A is a block diagram illustrating that a source software programmay be restored from image pieces of the image of the software program,which are each on a separate computer readable medium, according to theinvention.

FIGS. 6 and 7 are flow charts of methods of combining image pieces tocreate a re-combined image, according to the invention.

FIG. 8 is a block diagram illustrating one example of a suitablecomputing system environment in which the invention may be implemented.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIG. 1, in order to permit splitting of softwareitems (herein referred to as programs), each individual software program101 is converted into a source image 151 including an image ofdescriptive data of the software 101 and an image of the file data ofthe software 101. “Images” and “imaging” as used herein is also referredto as “disk images,” “disk imaging,” “volume images” and/or “volumeimaging.”

The descriptive data of the software 101 includes informationrepresenting the layout of the source image 151 and is referred to asmetadata 153. Essentially, metadata is information needed for a file orfile system such as a file directory to represent the file. The metadatamay include any one or more of the following: file names (short orlong), attributes, file times (e.g., create/access/modify), compressionformats, locations (e.g., directories), directory structures, securityinformation (e.g., access control list (ACL)) and/or stream names. Bysome definitions and in certain contexts, metadata may be defined toinclude any information which is not file data and may be viewed asincluding a header, an offset table and/or a signature. In thisdisclosure, the header, offset table and signature are separatelyillustrated for clarity.

The file data 155 includes any binary file data that is not metadataincluding but not limited to the following: the actual binary data of aparticular file, stream data and/or any data of significant size. Ingeneral, the image 151 is stored on a computer-readable medium as a datastructure of the software 101. As will be noted below in greater detail,one purpose of the image 151 is that it can be split into two or moreimage pieces which can be re-combined onto a destination medium tore-create the source image. Image 151 also includes a header 157identifying the image 151 and a signature 159 corresponding to the image151.

In addition, the image 151 includes an offset table 161 including thefollowing information for each file: a unique identification, location,size, any flags relating to the file and an optional hash of the file,as described below. As illustrated in FIG. 1, the metadata 153 points tothe offset table 161 and the offset table 161 points to the file data155. In particular, the metadata 153 has the unique identifier that canbe found in the offset table 161. The offset table 161 includes theoffset of the location of the file data in the image.

As shown in FIG. 1, the metadata 153 is positioned between the file data155 and the offset table 161, which is one preferred embodiment of thelayout of the image 151 according to the invention. The remainingfigures illustrate the metadata between the header and the file data forconvenience. In general, it is contemplated that the various informationmay be located in various places within the image so that the inventionis not intended to be limited to the locations illustrated.

FIG. 2 illustrates one optional method of converting the software 101into the source image 151 having a data structure which can be splitinto image pieces, each on a separate medium so that the image piecescan be re-combined by imaging to recreate the source image from theimage pieces. The method 200 of converting begins with generatingmetadata 152 of the software 101 at 202. Next, an offset table 161 ofthe source image 151 including a hash for each file is generated at 204.The hash list of the offset table 161 is a list of identifiers or othershort unique descriptors of each of the files which are presently in theimage 151. Initially, the hash list would be empty since no files haveyet been added to the image 151.

At 206, a first file, called file A, of the software 101 is read and at208 a hash of the read file A is generated. The hash of file A is anidentifier of the information in the file A. At 210, a search in theoffset table 161 for the hash and size of file A is conducted todetermine whether or not the hash for file A (and its size) is withinthe offset table 161 of the source image 151. If found at 212, thisindicates that file A is already a part of source image 151 and does nothave to be added to the image 151. At this point at 214, the metadata153 is updated to include the unique identification (ID) of file A whichis already in the source image 151.

If it is determined at 212 that the hash and size of file A are not inthe offset table 161 of the source image 151, the method proceeds to 216to add file A to the source image 151 and at 218 the hash and size offile A are added to the offset table 161 of the source image 151. Next,at 220 the new location of the file A in the source image 151 isdetermined and at 222 the offset table 161 of the source image 151 isupdated to include the new file location of file A. The method proceedsfrom 222 to 214 to update the metadata 153 of the source image 151 toinclude the unique identification of file A. Proceeding to 224, adetermination is made as to whether any more files need to be read fromthe first software 101. If there is more than one file as part of thesource software 101, the method returns to 206 to read the next file ofthe software 101. In the general case, A equals A+1 for each iterationof file reading. In the first iteration, A equaled 1 so that file 1 ofthe first software 101 was read. In the second iteration, A equals 2 sothe second file is read and so on until all of the N files of thesoftware 101 are read. After all the files are read, the method proceedsto 226 to create a header and signature for the image 151 and then ends.

The method of FIG. 2 may be performed manually or with the aid of a toolor performed automatically with a tool programmed to provide the processof FIG. 2. As noted above and as illustrated in FIG. 1, the hash of theoffset table 161 is optional for several reasons. First of all, it isnot necessary to employ a hash list to determine what file data is apart of the image 151. However, using hash identifiers in a hash listsimplifies and speeds up the process of determining whether or not anadditional file needs to be copied to an image. Second, the hash listneed not be a part of the image 151 and could be a temporary list usedonly during the process of converting the first software 101 into thesource image 151. However, there are some advantages to maintaining ahash list of each mounted image so that as additional information isadded to an image, or as an image is modified or updated, an up to datehash list of the image can be checked to determine whether or not theinformation that is being changed is redundant with other informationthat is already part of the image. In general, the metadata 152 andoffset table 161 for image 151 are created in memory and saved to a filewhich is added to image 151. If hash identifiers are to be part of theoffset table 161, the hash identifiers are added to the table when it iscreated in memory.

In cases where the first software or first image from which the imagepieces were created do not have duplicate files, the use of a hash toavoid duplicate files is unnecessary.

FIG. 3 is an exemplary embodiment of the invention illustratingschematically the layout of usable image pieces 1, 2 and 3 ondestination computer readable media #1, #2 and #3, respectively, splitfrom the source image 151 on a source computer readable medium 300. Inparticular, it can be seen that media #1, #2 and #3, referred to byreference characters 301, 302 and 303, each have stored thereon a datastructure which is a image piece (e.g., image pieces 1, 2 and 3,respectively) of the source image 151. In one form, it is contemplatedthat the media 301, 302, 303 have an available storage capacity which issmaller than the size of the source image 151. Thus, it would not bepossible to place the complete source image 151 on any of the media 301,302, 303. In other words, the invention allows the copying of the sourceimage onto removable media 301–303 even though the complete source image151 does not fit onto any one of the media. In another form, it iscontemplated that the media may have an available storage capacity or anavailable storage capacity which is larger than the source image 151. Inthis case, the image pieces of the source image are stored on the mediafor convenience in restoring, modifying, updating or otherwise handling.

Each data structure on media 301–303 includes selected files of thesource image 151. The particular files which are on each medium dependon user input and/or tool operation and are discussed in greater detailbelow. The data structure on each medium 301–303 also includes a headeridentifying each image piece as a portion of the source image 151. Thedata structure on each medium 301–303 also includes a metadataidentifying the files of the image piece. In general, the metadata ineach image piece may include all the files of the source image or justthe files of that image piece. The data structure on each medium 301–303also includes priority data from the source image 151 which correspondsto the selected files and non-priority data from the source image 151.This priority and non-priority data will be discussed below. Inaddition, the data structure on each medium 301–303 also includes asignature corresponding to the image piece and an optional offset table.

The data structure on any one or more of the media 301–303 also mayinclude selected files which are a restorable portion of the sourceimage 151 so that the image piece can be restored from the source image151. For example, medium 301 may include a plurality of files, each ofwhich can be opened or mounted so that each of the plurality of fileswithin the image piece 1 of medium 301 could be modified, updated orrestored independent of any changes to image pieces 302 or 303 andwithout reassembly of the image piece 1 with the other image pieces 2and 3. Specifically, the selected files may include a bootablecombination of files. As another example, image piece 302 may includeall files required by an engine or application so that the image piece302 is capable of initiating the operation of the engine or applicationof a computer. As another example, files may be grouped so that allfiles of a particular component end up in the same image piece. If aparticular component has 100 files associated with it, one might wantall the files to be in a particular image piece, although it may notmatter which image piece has all the files. With this configuration,when the files for the particular component are needed, one need onlyuse the particular image piece so that access to the other image piecesis unnecessary.

FIG. 4 is exemplary flow chart illustrating operation of a method andtool according to the invention for creating image pieces, each on aseparate computer readable medium, from a source image according to theinvention.

Initially, a user either manually or through the use of a software toolassigns priority to the files of the source image 151 at 402. Thepriority is based on the result required or desired, such as to create abootable piece and/or to create a piece for use with an engine. Forexample, all the files needed for booting may be assigned to the firstmedium 301 on which the image piece #1 will be copied. Next, the media301 on which the image piece #1 will be copied is inserted into a device(e.g. 154, 156, 160 of FIG. 8) which will copy the image piece onto themedium 301 at 404. At this point, the user or tool writes a header andmetadata to the computer readable medium 301 at 406. Next, the files arecopied onto the medium 301. In particular, priority files are firstcopied onto the medium 301 at 408 and then remaining files are copiedonto the medium 301 at 410 until the size limit of the medium is reached(or until a designated size is reached, as noted below). At 412, asignature is written onto the medium along with an optional offsettable. At 414 it is determined whether or not additional files need tobe copied. In most cases, if only one medium with only image piece #1has been generated, additional files need to be copied from the sourceimage 151 since the medium 301 is smaller than the image. Thus, themethod and tool proceed to 416 where a second medium 302 is insertedinto the copying device. At 418, a header and metadata for the mediumare written onto the second medium and the process proceeds to step 410to continue copying remaining files onto the second medium 302 until thesize limit of the second medium is reached. (If additional priorityfiles need to be copied to the second medium, the process would proceedfrom 418 to 408. It is not necessary to have and swap the removablemedium to split an image. For example, the image may be split on a harddrive into particular sized pieces because the particular size is thecapacity of a removable medium. Thus, it would not be necessary to splitthe individual pieces; the pieces can remain on the hard drive andfunction as the software program. At a time when a copy of the softwareprogram is need, image pieces on the hard drive can be copied ortransferred to individual media. This would be common in a case where asoftware tool for splitting images according to the invention wouldbreak the image into pieces equal to or less than the capacity of aCD-ROM, and then another tool could be used to burn those pieces to aCD.

After writing a signature at 412 and an optional offset table, themethod proceeds to 414 again to determine if additional files need to becopied. If so, the method proceeds again to 416 and so on to copy anyremaining files on any additional medium that may be needed or desired.If no additional files need to be copied, the process ends at 420.

As a specific example, FIG. 4 illustrates the operation of a softwaretool which splits a source image 151 into two or more image pieces(e.g., image pieces #1, #2 and #3) so that each image piece will fitonto a computer readable medium 301, 302, 303 having an availablestorage capacity which is smaller than the size of the source image 151,as noted above. In one form, the software tool and process according tothe invention would include a selecting tool (accomplishing priorityassignments at 402), a splitting tool (accomplishing file copying at 408and 410) and a chaining tool (accomplishing labeling at 406, 412 and418). The selecting tool would be used by the user and would beresponsive to user input for designating which files of the source image151 would be included in each image piece #1, #2 and #3 stored on media301–303, respectively. The splitting tool then groups the filesdesignated by the selecting tool under the user's control in accordancewith the corresponding image piece which will include the file. Next, achaining tool labels each of the image pieces. The chaining tool createsa unique header for each of the image pieces, a metadata file for eachof the image pieces and a unique signature for each of the image pieces.

The software tool and process of the invention allows each of the imagepieces to be independent of each other so that at least one of the imagepieces is a restorable portion of the source image 151. In addition,this independent arrangement allows each image piece to be modified,updated, viewed, read or restored independently of the other imagepieces and without reassembly of the image pieces. In particular, eachof the image pieces is adapted to include a plurality of files, suchthat each image piece can be opened so that the information contained inthe image piece can be read or mounted. As a result, each of theplurality of files within each image piece can be added to, removed fromor extracted from the image piece independent of any changes to theother image pieces of the source image and without reassembly of theimage pieces. As noted above, an image piece may be configured to bebootable so that the bootable combination of files are a unique portionof one of the image pieces. In other words, this minimizes files thattake up duplicate space on the computer readable media 301–303 on whichthe image pieces are stored.

As noted above, the user or tool may determine to assign priority sothat a particular image piece includes all the files which would berequired by an application so that the particular image piece is capableof initiating operation of the application on a computer independent ofthe computer accessing the other image pieces of the source image 151.As another example, priority may be assigned so that related componentresources are included on the specific image piece, such as image piece#1 on media 301, so that the source image 151 can be restored on acomputer with a minimum amount of changing between the media 301 and theother media 302, 303. As another example, each of the image pieces maybe part of a recovery media such that each of the image pieces mayinclude a minimal bootable operating system.

FIG. 4 also illustrates a method of splitting the source image 151 intotwo or more image pieces so that each of which will fit onto a computerreadable medium having an available storage capacity which is smallerthan the size of the source image 151 itself. In this context, themethod includes designating which files of the source image will beincluded in each image piece at 402 and grouping the designated filesinto their corresponding image pieces at 404 et seq. As part of thegrouping, the image pieces are labeled by writing a header and metadatafor the image piece at 406 or 418; by copying priority data whichcorresponds to the designated files from the source image 151 to theimage piece at 408; and by copying non-priority data from the sourceimage 151 to the image piece at 408. In addition, a signature andoptional offset table are added to the image piece at 412. The signatureand/or offset table corresponds to the contents of the image piece. Itis contemplated that the grouping comprises creating the image piece byimaging the files from the source image 151 to the computer readablemedium 301–303. Optionally, the user or tool may specify the size ofeach of the image pieces and/or specify which files of the source imagewill be included in each of the image pieces.

As another aspect of the invention, FIG. 4 illustrates a method ofcreating from a source image 151 an image piece #1, #2, #3 which willfit onto a computer readable medium 301, 302, 303 having an availablestorage capacity which is smaller than the size of the source image 151.In this method, the remaining files that are copied at 410 are limitedto a specified size of the image piece as specified by a user or by atool. Files of the source image 151 that will be included in the imagepiece are designated at 402 and the image piece is created at 408, 410from the designated files. The remainder of the method is as notedabove.

FIG. 5 is a block diagram illustrating an exemplary destinationcomputer-readable medium (CRM) 500 on which a re-combined imagecorresponding to the source image 151 may be created from image pieces#1, #2, #3 which are each on a separate computer readable medium 501,502, 503, respectively, according to the invention. In particular, FIG.5 illustrates a computer readable medium 500 having stored thereon adata structure in the form of a re-combined image formed by combiningimage pieces #1, #2, #3 that originate from a source image 151 (see FIG.3). Thus, the re-combined image corresponds to the source image 151. Asnoted with regard to FIG. 3, each of the image pieces #1, #2 and #3 ison a computer readable medium 301, 302, 303, respectively. Each mediumhas an available storage capacity which is smaller than the size of thesource image 151. Even though the image may fit on an empty medium,there might be other data besides the image on there that forces us tospan. Medium 500 may be referred to as a destination computer readablemedium because it is the destination of the re-combined image to becreated by combining the image pieces. As with the original source image151, the re-combined image includes a header identifying the re-combinedimage, a metadata identifying the files of the re-combined image,priority data from the image pieces #1, #2, #3, non-priority data fromthe image pieces, and a signature corresponding to the re-combinedimage. One difference between the re-combined image and the source imageis that the source image 151 originates from software 101 (see FIG. 1)whereas the re-combined image originates from image pieces #1, #2, #3(see FIG. 5) which each originate from the source image 151 (see FIG.3). Operationally, the re-combined image and the source image 151 areindistinguishable.

FIG. 5A is a block diagram illustrating that one or more applications ofthe source software program 101 may be restored from the image pieces 1,2 and 3 of the image of the software program, which are each on aseparate computer readable medium 501, 502, 503, according to theinvention. For example, suppose the first software 101 has a wordprocessing application and a spreadsheet application. Suppose furtherthat the image 151 of the first software 101 includes five (5) imagepieces. According to the invention, image pieces 1 and 2 may bedesignated to include the word processing application and image pieces3, 4 and 5 may be designated to include the spreadsheet applicationThus, the word processing application may be restored from image pieces1 and 2 without the need for restoring the entire image 151 or withoutthe need for restoring the spreadsheet application or without the needfor combining all five image pieces. Similarly, the spreadsheetapplication may be restored from image pieces 3, 4 and 5 without theneed for restoring the entire image 151, without the need for restoringthe word processing application or without the need for combining allfive image pieces.

FIG. 6 is a flow chart of a method and tool for combining image piecesto create a re-combined image corresponding to the source image 151 fromwhich the image pieces were created, according to the invention.

In particular, FIG. 6 illustrates a method of combining image pieces tocreate a re-combined image or medium 500 as illustrated in FIG. 5 fromimage pieces #1, #2 and #3 on media 501, 502 and 503, respectively. Afirst determination of the method relates to whether or not a previousimage piece has been copied to the destination medium 500. If a firstimage piece #1 is to be copied to the destination medium 500 and noprevious image pieces have been copied to the destination medium 500, asdetermined at 602, the method proceeds to 604 to copy file data from thefirst image piece to the destination medium 500. Next at 606, a headeris created for the re-combined image based on the information of thefirst image piece that has been copied to the re-combined image. At 608,metadata and an optional offset table are created for the re-combinedimage to identify and point to the information which is now a part ofthe re-combined image on the medium 500. At 610, a signature of there-combined image is created and the process proceeds to step 612 todetermine whether or not another image piece needs to be copied. Ifthere are no other image pieces, the process ends. Otherwise, theprocess proceeds to 614 where the file data from the next image piece iscopied to the medium 500. At 616, the header of the re-combined image isupdated with information to include the files copied from the next imagepiece to the re-combined image on the destination media. At 618 themetadata and offset table of the re-combined image are updated relatingto the newly added information. Finally at 620, the signature of there-combined image is updated. The process again returns to 612 until allimage pieces have been copied to the medium 500.

FIG. 6 (and also FIG. 7 as noted below) illustrate the operation of asoftware tool and/or method which combines two or more image pieces #1,#2, #3 of a source image 151 into a re-combined image on the destinationmedium 500. As a result, the re-combined image corresponds to the sourceimage 151. As noted above, this is particularly applicable in the casewhere each of the image pieces #1, #2, #3 is on a computer readablemedium 301–303 having an available storage capacity which is smallerthan the size of the source image 151. The software tool and/or methodhas three aspects. First, a copying tool or process is responsive touser input or tool instructions for copying files of the image piecesonto the destination medium 500 (see FIG. 6, reference character 604).Second, a combining tool or process combines the copied files into there-combined image on the destination medium 500 (see FIG. 6, referencecharacter 614). Third, a chaining tool labels the re-combined image onthe destination medium 500 (see FIG. 6, reference characters 606, 608,616, 618). As noted above, one advantage of this process and tool isthat related component resources may be included in the same image pieceso that the source image 151 can be re-combined on the destinationcomputer readable medium 151 with a minimum amount of changing betweenthe computer readable media storing the image pieces #1, #2, #3 of thesource image 151.

Viewed another way, FIG. 6 illustrates a method of combining three imagepieces #1, #2, #3 of a source image 151 into a re-combined image ondestination medium 500 by copying files of the image pieces onto thedestination medium 500 in response to user input, by combining thecopied files into the re-combined image on the destination medium 500and by labeling the re-combined image on the destination medium 500. Inthis context, the labeling includes writing a header for the re-combinedimage from each image piece, writing metadata for the recombined imagefor each image piece, copying priority data from the image pieces to therecombined image, copying non-priority data from the image piece to therecombined image; and adding a signature to the recombined image whichsignature corresponds to the contents of the recombined image.

From an imaging perspective, FIG. 6 also illustrates a method ofcombining multiple image pieces #1, #2, #3 of a source image 151 into are-combined image corresponding to the source image 151 by imaging there-combined image from the image pieces, writing a header for there-combined image wherein the header corresponds to the files of there-combined image, writing a metadata for the re-combined image whereinthe metadata corresponds to the files of the re-combined image andadding a signature to the re-combined image which signature correspondsto the contents of the re-combined image.

FIG. 7 is another flow chart of another method and tool for combiningimage pieces to create a re-combined image, according to the invention.Referring to FIG. 7, a method is illustrated of combining several imagepieces into a single re-combined image which corresponds to a sourceimage such as source image 151. Initially, the first image piece iscopied to a destination medium at 702. In general, the first image pieceforms an image to which files will be added to create a re-combinedimage corresponding to the source image 151. A combined offset tableincluding the hash list of identifiers of all the files identified bythe metadata of the first image piece is next generated at 704. Thefirst image piece eventually becomes the re-combined image after allother image pieces are added to it. Thus, the first image piece (andanything added to it) is referred to as the re-combined image during theprocess of adding the other image pieces to the first image piece.

The remainder of the substantive portion of the method illustrated inFIG. 7 of adding the other image pieces to the first image piececorresponds to the substantive portion of the method of FIG. 2. Inparticular, each file in the next image is read at 706, a hash for eachfile is generated at 708, and at 710 a search for the hash and size ofthe read file is made within the hash list of the offset table of there-combined image (initially, the first image piece). If at 712 the hashand size of the read file are in the offset table indicating that thefile data is part of the re-combined image, the metadata of therecombined image is updated at 714 to include the unique identificationof the file in the re-combined image. If at 712 the hash of the readfile is not in the hash list, the file is added to the recombined imageat 716, the hash and size of the file are added to the offset table ofthe recombined image at 718, the new location of the file is determinedat 720 and the offset table of the image is updated to include the newlocation of the new file at 722. Next, the metadata of the image isupdated at 714 to include the unique identification of the file. If thehash and size of the read file are found in the offset table, processingalso continues at 714. This is done for each file of the next image.When all the files of all image pieces have been considered, asdetermined at 724, a header and signature of the recombined image iscreated at 726 and the re-combined image now becomes the source imagefrom which the image pieces were created. FIG. 7 also illustrates at 728that file data of the re-combined image can be modified, updated orrestored.

FIG. 8 shows one example of a general purpose computing device in theform of a computer 130. In one embodiment of the invention, a computersuch as the computer 130 is suitable for use in the other figuresillustrated and described herein. For example, such a device may employor may be used to create a source image, an image piece and/or arecombined image. Computer 130 has one or more processors or processingunits 132 and a system memory 134. In the illustrated embodiment, asystem bus 136 couples various system components including the systemmemory 134 to the processors 132. The bus 136 represents one or more ofany of several types of bus structures, including a memory bus or memorycontroller, a peripheral bus, an accelerated graphics port, and aprocessor or local bus using any of a variety of bus architectures. Byway of example, and not limitation, such architectures include IndustryStandard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus,Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA)local bus, and Peripheral Component Interconnect (PCI) bus also known asMezzanine bus.

The computer 130 typically has at least some form of computer readablemedia. Computer readable media, which include both volatile andnonvolatile media, removable and non-removable media, may be anyavailable medium that can be accessed by computer 130. By way of exampleand not limitation, computer readable media comprise computer storagemedia and communication media. Computer storage media include volatileand nonvolatile, removable and non-removable media implemented in anymethod or technology for storage of information such as computerreadable instructions, data structures, program modules or other data.For example, computer storage media include RAM, ROM, EEPROM, flashmemory or other memory technology, CD-ROM, digital versatile disks (DVD)or other optical disk storage, magnetic cassettes, magnetic tape,magnetic disk storage or other magnetic storage devices, or any othermedium that can be used to store the desired information and that can beaccessed by computer 130. Communication media typically embody computerreadable instructions, data structures, program modules, or other datain a modulated data signal such as a carrier wave or other transportmechanism and include any information delivery media. Those skilled inthe art are familiar with the modulated data signal, which has one ormore of its characteristics set or changed in such a manner as to encodeinformation in the signal. Wired media, such as a wired network ordirect-wired connection, and wireless media, such as acoustic, RF,infrared, and other wireless media, are examples of communication media.Combinations of the any of the above are also included within the scopeof computer readable media.

The system memory 134 includes computer storage media in the form ofremovable and/or non-removable, volatile and/or nonvolatile memory. Inthe illustrated embodiment, system memory 134 includes read only memory(ROM) 138 and random access memory (RAM) 140. A basic input/outputsystem 142 (BIOS), containing the basic routines that help to transferinformation between elements within computer 130, such as duringstart-up, is typically stored in ROM 138. RAM 140 typically containsdata and/or program modules that are immediately accessible to and/orpresently being operated on by processing unit 132. By way of example,and not limitation, FIG. 8 illustrates operating system 144, applicationprograms 146, other program modules 148, and program data 150.

The computer 130 may also include other removable/non-removable,volatile/nonvolatile computer storage media. For example, FIG. 8illustrates a hard disk drive 154 that reads from or writes tonon-removable, nonvolatile magnetic media. FIG. 8 also shows a magneticdisk drive 156 that reads from or writes to a removable, nonvolatilemagnetic disk 158, and an optical disk drive 160 that reads from orwrites to a removable, nonvolatile optical disk 162 such as a CD-ROM orother optical media. Other removable/non-removable, volatile/nonvolatilecomputer storage media that can be used in the exemplary operatingenvironment include, but are not limited to, magnetic tape cassettes,flash memory cards, digital versatile disks, digital video tape, solidstate RAM, solid state ROM, and the like. The hard disk drive 154, andmagnetic disk drive 156 and optical disk drive 160 are typicallyconnected to the system bus 136 by a non-volatile memory interface, suchas interface 166.

The drives or other mass storage devices and their associated computerstorage media discussed above and illustrated in FIG. 8, provide storageof computer readable instructions, data structures, program modules andother data for the computer 130. In FIG. 8, for example, hard disk drive154 is illustrated as storing operating system 170, application programs172, other program modules 174, and program data 176. Note that thesecomponents can either be the same as or different from operating system144, application programs 146, other program modules 148, and programdata 150. Operating system 170, application programs 172, other programmodules 174, and program data 176 are given different numbers here toillustrate that, at a minimum, they are different copies.

A user may enter commands and information into computer 130 throughinput devices or user interface selection devices such as a keyboard 180and a pointing device 182 (e.g., a mouse, trackball, pen, or touch pad).Other input devices (not shown) may include a microphone, joystick, gamepad, satellite dish, scanner, or the like. These and other input devicesare connected to processing unit 132 through a user input interface 184that is coupled to system bus 136, but may be connected by otherinterface and bus structures, such as a parallel port, game port, or aUniversal Serial Bus (USB). A monitor 188 or other type of displaydevice is also connected to system bus 136 via an interface, such as avideo interface 190. In addition to the monitor 188, computers ofteninclude other peripheral output devices (not shown) such as a printerand speakers, which may be connected through an output peripheralinterface (not shown).

The computer 130 may operate in a networked environment using logicalconnections to one or more remote computers, such as a remote computer194. The remote computer 194 may be a personal computer, a server, arouter, a network PC, a peer device or other common network node, andtypically includes many or all of the elements described above relativeto computer 130. The logical connections depicted in FIG. 8 include alocal area network (LAN) 196 and a wide area network (WAN) 198, but mayalso include other networks. Such networking environments arecommonplace in offices, enterprise-wide computer networks, intranets,and global computer networks (e.g., the Internet).

When used in a local area networking environment, computer 130 isconnected to the LAN 196 through a network interface or adapter 186.When used in a wide area networking environment, computer 130 typicallyincludes a modem 178 or other means for establishing communications overthe WAN 198, such as the Internet. The modem 178, which may be internalor external, is connected to system bus 136 via the user input interface184, or other appropriate mechanism. In a networked environment, programmodules depicted relative to computer 130, or portions thereof, may bestored in a remote memory storage device (not shown). By way of example,and not limitation, FIG. 8 illustrates remote application programs 192as residing on the memory device. It will be appreciated that thenetwork connections shown are exemplary and other means of establishinga communications link between the computers may be used.

Generally, the data processors of computer 130 are programmed by meansof instructions stored at different times in the variouscomputer-readable storage media of the computer. Programs and operatingsystems are typically distributed, for example, on floppy disks orCD-ROMs. From there, they are installed or loaded into the secondarymemory of a computer. At execution, they are loaded at least partiallyinto the computer's primary electronic memory. The invention describedherein includes these and other various types of computer-readablestorage media when such media contain instructions or programs forimplementing the steps described below in conjunction with amicroprocessor or other data processor. The invention also includes thecomputer itself when programmed according to the methods and techniquesdescribed herein.

For purposes of illustration, programs and other executable programcomponents, such as the operating system, are illustrated herein asdiscrete blocks. It is recognized, however, that such programs andcomponents reside at various times in different storage components ofthe computer, and are executed by the data processor(s) of the computer.

Although described in connection with an exemplary computing systemenvironment, including computer 130, the invention is operational withnumerous other general purpose or special purpose computing systemenvironments or configurations. The computing system environment is notintended to suggest any limitation as to the scope of use orfunctionality of the invention. Moreover, the computing systemenvironment should not be interpreted as having any dependency orrequirement relating to any one or combination of components illustratedin the exemplary operating environment. Examples of well known computingsystems, environments, and/or configurations that may be suitable foruse with the invention include, but are not limited to, personalcomputers, server computers, hand-held or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputers, mainframe computers,distributed computing environments that include any of the above systemsor devices, and the like.

The invention may be described in the general context ofcomputer-executable instructions, such as program modules, executed byone or more computers or other devices. Generally, program modulesinclude, but are not limited to, routines, programs, objects,components, and data structures that perform particular tasks orimplement particular abstract data types. The invention may also bepracticed in distributed computing environments where tasks areperformed by remote processing devices that are linked through acommunications network. In a distributed computing environment, programmodules may be located in both local and remote computer storage mediaincluding memory storage devices.

In operation, computer 130 executes computer-executable instructionssuch as those illustrated in FIG. 2 to convert the software program 101into the source image 151. In addition, computer 130 executescomputer-executable instructions such as those illustrated in FIG. 4 tocreate image pieces #1, #2, #3 on media 301–303, respectively. Inaddition, computer 130 executes computer-executable instructions such asthose illustrated in FIGS. 6 and 7 to create a re-combined image fromthe image pieces.

The following examples illustrate the invention. In this example, anexemplary image corresponds to an operating system (OS) and one or moreapplication programs. The size of the exemplary image exceeds theavailable storage capacity of a single storage medium such as a CD-ROM.As such, the exemplary image spans a set of multiple CD-ROMs accordingto the invention. The first CD-ROM in the set (e.g., image piece #1 inFIG. 5A) includes any files needed to boot into an environment forinstalling the OS of the image to the destination medium. In addition,the first CD-ROM in the set includes any files needed to initiate setupof the OS and/or the application programs of the exemplary image. Eachof the remaining CD-ROMs in the set (e.g., image piece #2 and imagepiece #3 in FIG. 5A) corresponds to components of the OS or theapplication programs. The files for each component are grouped andstored on these remaining CD-ROMs. In this example, in response to arequest for a specific component of the exemplary image, there-combining software of the invention restores the requested componentfrom the image piece corresponding to the requested component directlyto the destination computer without re-combining all the image pieces.

In a further example, the user may later request to add a component thatwas not installed initially. The user installs the requested componentby accessing the image piece that corresponds to the requestedcomponent. In this example, the user mounts the CD-ROM and accesses thefiles that need to be installed.

When introducing elements of the present invention or the embodiment(s)thereof, the articles “a,” “an,” “the,” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions, products,and methods without departing from the scope of the invention, it isintended that all matter contained in the above description and shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

1. A software tool stored on a computer storage medium which splits asource image into two or more image pieces, each of which fits onto acomputer readable medium having an available storage capacity which issmaller than the size of the source image, said software toolcomprising: a selecting tool responsive to user input for designatingwhich files of the source image to be included in each image piece; asplitting tool which groups the designated files into theircorresponding image piece, wherein each of the image pieces is adaptedto include a plurality of files, each of which can be opened or mountedso that each of the plurality of files within each image piece can beadded, removed or extracted from the image piece independent of anychanges to the other image pieces of the source image and withoutreassembly of the image pieces; and a chaining tool which labels each ofthe image pieces.
 2. The tool of claim 1 wherein each of the imagepieces is adapted to be independent of each other and comprises arestorable portion of the source image so that the image piece can bemodified, updated or restored without reassembly of the image pieces. 3.The tool of claim 1 wherein one or more of the image pieces includes abootable combination of files.
 4. The tool of claim 3 wherein thebootable combination of files are a unique portion of one of the imagepieces so that the files do not take up duplicate space on the computerreadable medium on which the image piece is stored.
 5. The tool of claim1 wherein each of the image pieces includes all files required by aparticular application so that the one image piece is capable ofinitiating operation of the particular application.
 6. The tool of claim5 wherein the particular application is a setup engine so that the oneimage piece is capable of initiating setup.
 7. The tool of claim 1wherein related component resources are included on a particular one ofthe image pieces so that the source image can be restored on a computerwith a minimum amount of changing between the computer readable mediastoring the image pieces of the source image.
 8. The tool of claim 1wherein the chaining tool creates a unique header for each of the imagepieces and a metadata file for each of the image pieces.
 9. The tool ofclaim 1 wherein undesignated files of the image are stored as part ofany of the image pieces until a limit for the size of the computerreadable medium of the image piece is reached.
 10. The tool of claim 1wherein the chaining tool creates a unique signature for each of theimage pieces.
 11. The tool of claim 1 wherein each of the image piecesis part of a recovery media and wherein each of the image piecesincludes a minimal bootable operating system.
 12. A method of splittinga source image into two or more image pieces, each of which fits onto acommuter readable medium having an available storage capacity which issmaller than the size of the source image, said method comprising:designating which files of the source image to be included in each imagepiece; grouping the designated files into their corresponding imagepieces; and labeling the image pieces, including: writing a header forthe image piece wherein the header corresponds to the designated files;writing a metadata for the image piece wherein the metadata correspondsto the designated files; copying priority data which corresponds to thedesignated files from the source image to the image piece; copyingnon-priority data from the source image to the image piece; and adding asignature to the image piece which signature corresponds to the contentsof the image piece.
 13. The method of claim 12 wherein said groupingcomprises creating the image piece by copying the files from the sourceimage to the computer readable medium of the image piece.
 14. The methodof claim 12 wherein said designating comprises specifying the size ofeach of the image pieces and specifying which files of the source imageto be included in each of the image pieces.
 15. The method of claim 12,wherein one or more computer readable media have computer-executableinstructions for performing the method of claim
 12. 16. A method ofcreating from a source image an image piece which fits onto a computerreadable medium having an available storage capacity which is smallerthan the size of the source image, said method comprising: specifyingthe size of the image piece; designating which files of the source imageto be included in the image piece; creating the image piece from thedesignated files; writing a header for the image piece wherein theheader corresponds to the designated files; writing a metadata for theimage piece wherein the metadata corresponds to the designated files;copying priority data which corresponds to the designated files from thesource image to the image piece; copying non-priority data from thesource image to the image piece; and adding a signature to the imagepiece which signature corresponds to the contents of the image piece.17. A software tool stored on a computer storage medium having computerexecutable components for combining two or more image pieces of a sourceimage into a re-combined image corresponding to the source image,wherein each of the image pieces is on a computer readable medium havingan available storage capacity which is smaller than the size of thesource image, and wherein the re-combined image is stored on adestination computer readable medium, said software tool comprising: acopying tool responsive to user input for copying files of the imagepieces onto the destination computer readable medium; a combining toolwhich combines the copied files into the re-combined image on thedestination computer readable medium; and a chaining tool which labelsthe re-combined image on the destination computer readable medium. 18.The tool of claim 17 wherein related component resources are included onthe same image piece so that the source image can be re-combined on thedestination computer readable medium with a minimum amount of changingbetween the computer readable media storing the image pieces of thesource image.
 19. A method of combining two or more image pieces of asource image into a re-combined image corresponding to the source image,wherein each of the image pieces is stored on a computer readable mediumhaving an available storage capacity which is smaller than the size ofthe source image, and wherein the re-combined image is on a destinationcomputer readable medium, said method comprising: copying files of theimage pieces onto the destination computer readable medium in responseto user input; combining the copied files into the re-combined image onthe destination computer readable medium; and labeling the re-combinedimage on the destination computer readable medium.
 20. The method ofclaim 19 wherein said labeling comprises: writing a header for therecombined image from each image piece; writing a metadata for therecombined image for each image piece; copying priority data from theimage pieces to the recombined image; copying non-priority data from theimage piece to the recombined image; and adding a signature to therecombined image which signature corresponds to the contents of therecombined image.
 21. The method of claim 19 wherein said groupingcomprises creating the image piece by imaging the files from the sourceimage to the computer readable medium of the image piece.
 22. The methodof claim 19 wherein said designating comprises specifying the size ofeach of the image pieces and specifying which files of the source imageis included in each of the image pieces.
 23. The method of claim 19,wherein one or more computer readable media have computer-executableinstructions for performing the method of claim
 18. 24. A method ofcombining two or more image pieces of a source image into a re-combinedimage corresponding to the source image, wherein each of the imagepieces is on a computer readable medium having an available storagecapacity which is smaller than the size of the source image, and whereinthe re-combined image is on a destination computer readable medium, saidmethod comprising: imaging the re-combined image from the image pieces;writing a header for the re-combined image wherein the headercorresponds to the files of the re-combined image; writing a metadatafor the image piece wherein the metadata corresponds to the files of there-combined image; adding a signature to the re-combined image whichsignature corresponds to the contents of the re-combined image.
 25. Themethod of claim 24 wherein one or more computer readable media havecomputer-executable instructions for performing the method of claim 18.